The present invention relates to a method and a device for recognizing the condition of a road, particularly rough surface areas or unevenness of the edge of a road, by electromagnetic waves, such as light, according to the principle of measuring the transit time, in which a transmitter emits measuring beams and a receiver receives reflected measuring beams which generate signals to be analyzed at the time of reception.
Previously known apparatuses make it possible to obtain a CCD image of a specific road area by complex computing operations under favorable environmental conditions and with an expensive display system. However, this type of a display supplies no information on the distance, for example, of a displayed rough spot of the road surface.
On the other hand, distance measuring apparatuses according to the principle of measuring the transit time of signals which take a bearing on objects or scan them point by point have been known for some time. See, for example, German patent documents DE 32 19 423 A1, DE 34 47 015 A1.
It is an object of the invention to provide a method and a device for recognizing the condition of the road, particularly rough areas on the surface and at the edge of the road and their distance from a vehicle by electromagnetic radiation, using a transmitter to emit measuring beams and a receiver to transduce reflected measuring beams into signals to be fed to a processing and analysis unit. The apparatus needs to supply an image of the road surface condition in a simple manner and at the same time -- particularly in the case of rough areas -- provide information concerning the relative position/distance of the rough areas.